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Fall 2008 Subsidence and Geologic Field Observations <br />Box Canyon, Apache Rocks, and South of Divide Mining Areas <br />i No landslide or slope instability observations were noted along this traverse. <br />5.11 Traverse K-K' <br />This traverse is along the Dry Fork road. It begins at the Monument Dam (Minnesota Reservoir) <br />and proceeds eastward past the fork with Deer Creek road and Horse Gulch road and then <br />southeastward to the point where the road crosses Deep Creek (see Maps 2 and 4). Portions of <br />this traverse are above planned Longwall Panels E1 through E5 where the overburden depth to <br />the E-seam ranges from 400 to 1,200 feet. The extreme western end of this traverse is in the <br />immediate vicinity of Minnesota Reservoir and expected to be outside of proposed E-seam <br />mining influences. <br />Thick soil and colluvium derived primarily from the Wasatch Formation were observed along <br />this traverse. The estimated thickness of the surficial material ranges from 75 to 250 feet, or <br />perhaps locally 300 feet. <br />Newly reconstructed Monument Dam and grading near the south (left) abutment were observed. <br />Figure 33 shows the extent of material excavation which occurred to readjust/rebalance the toe <br />load of the landslide to reduce the lateral pressure on the south side of the left abutment and to <br />buttress the downstream portion of Monument Dam. Minnesota Reservoir was virtually empty at <br />the time of our visit with all surface inflows allowed to pass through the structure. <br />No subsidence related features were observed along this traverse. <br />• <br />831-032.790 Wright Water Engineers, Inc. Page 48 <br />December 2008